session_start()

session_start function creates a session or resumes the current one based on the  current session id that is being passed via a request like GET, POST, or a cookie. For using named session, first you will have to call session_name() before calling session_start(). The session_start function returns TRUE if the session starts successfully otherwise it returns FALSE.

Syntax

session_start();

Example:

<?php
session_start();
echo "your session ID is ".session_id();
?>

In the output, you will get your session ID. 

Related Tags for Starting the session.: